1. Field of the Invention
This invention relates to a method for fixing a mud flap to a motor vehicle. More particularly, this invention relates to a method for fixing a mud flap, comprising a main flap body and an adapter protrusion extending from the upper end of the main flap body, to a motor vehicle wherein the mud flap is screwed or clamped to the vehicle body so that at least part of the adapter protrusion and, optionally, part of the main flap part engages the motor vehicle body.
2. Description of the Prior Art
Such mud flaps are known (British Pat. No. 2,037,679 corresponding to U.S. Pat. No. 4,315,634) and are widely used both as front wheel and rear wheel mud flaps. Generally, such mud flaps are fixed in such a way that the inner marginal area of the adapter protrusion, i.e. the area which is adjacent to the adapter protrusion edge and located opposite the common outer edge of the main flap body and the adapter protrusion, is engaged with the fender fold of a motor vehicle. The fender fold, as is well-known, being the in-turned edge of a motor vehicle at the mudguard or fender. The mud flap is oriented in this position and is then fixed to the vehicle, for example, with clamps engaging around the fender fold and the marginal area of the adapter protrusion or with screws penetrate the marginal area and screwed into the fender fold. This marginal area of the adapter protrusion can be bent somewhat out of the plane of the main flap body and the remainder of the adapter protrusion, in order to bring about a compensation to the fold slope, and/or the inner marginal area of the adapter protrusion can be provided with a bendable reinforcing plate extending up to the main flap body (as known from British Pat. No. 1,442,226 corresponding U.S. Pat. No. 3,953,053), in order to permit a subsequent orientation of the fitted mud flap.
When fitting such mud flaps to motor vehicles, a surface of the mud flap, conventionally a surface formed by the inner marginal area of the adapter protrusion, engages with the vehicle body at the fender fold and is pressed by clamps or screws against the vehicle body. Due to this flat engagement, which is obviously not ideally flat, between the adapter protrusion surface and the adjacent vehicle body, small gaps exist in which water can collect. Due to the dimensions of these gaps and the resulting capillary forces, the water can be kept in said gaps and can be sucked into adjacent, even smaller gaps. These moisture deposits are not removed by the slipstream in dry weather and instead only gradually disappear due to evaporation. Thus, such moisture deposits lead to corrosion of the vehicle body.
Due to the engagement of part of the mud flap member on the vehicle body, discolorations to adjacent body areas can occur, because plasticizer migrates out of the mud flap material, which generally is rubber or a plastic. When choosing the mud flap material, it is necessary to take account of the fact that such plasticizer migrations must be prevented to the greatest possible extent, i.e. a relatively high-quality material must be used for the manufacture of the mud flaps.
In another known mud flap with a main flap body and an adapter protrusion (British published application No. 2,042,619 corresponding to U.S. Pat. No. 4,323,262), roughened portions are provided on the inner marginal area of the adapter protrusion engaged with the fender fold to give the mud flap a better hold on the latter. These roughened portions are naturally relatively flat, so that on engaging the fender fold gaps form between the surface of the adapter protrusion and the fender fold, which have such a limited height that considerable capillary forces act on the entering water, so that the water is generally held even more "firmly" between the adapter protrusion and the vehicle body and, consequently, more "firmly" in contact with the latter than in the case of the previously described mud flaps with a smooth surface. In the case of such mud flaps there is still a risk of plasticizer migration onto the vehicle body.